TT roadster promotes every Audi offering

It is an article of dogma in the automobile industry that a two-seat sports car confers a halo that enhances the sales of a manufacturer’s entire lineup.

So even though Pontiac has been struggling, the Solstice helps prop up the brand. The same goes for Saturn and the Sky, a Solstice sibling. Chevrolet has the Corvette, Dodge the Viper and Ford the GT. Among the foreign manufacturers, Honda offers the S-2000, Nissan the 350Z, Mazda the MX-5 Miata, Mitsubishi the Eclipse, Lexus the SC, Mercedes-Benz the McLaren — SL and SLK — BMW the Z cars, and Audi has the TT. Porsche so far only makes two-seaters, except for its Cayenne SUVs.

Germany’s Audi is a relative newcomer, having introduced the TT in 2000. Now, for 2008, it has revamped the small sports car. It is larger and more powerful but weighs less.

The TT comes in two versions: coupe and roadster. The coupe has a no-account back seat, so should be considered a two-seater anyway.

Both cars have an aluminum space frame and body panels. Overall, the coupe is 69 percent aluminum, and the roadster is 58 percent aluminum. The base TT, in both versions, has front-wheel drive and comes with only one drivetrain: a 200-horsepower, 2-liter, turbocharged four-cylinder engine linked to Audi’s S Tronic transmission, which is a six-speed dual-clutch gearbox that shifts automatically or manually without a clutch pedal.

It manages better fuel economy than a conventional manual, and because the dual clutches pre-select the gears, it snaps off shifts with uncanny smoothness and rapidity.

The 2-liter engine with the S Tronic transmission propels the TT coupe to 60 miles an hour in slightly more than six seconds and delivers 23 city/31 highway miles per gallon on the EPA’s new, more rational fuel economy rating.

Despite the sophistication of the dual-clutch transmission, diehard enthusiasts likely will prefer the more powerful TT, the subject here, which has a 250-horsepower, 3.2-liter V-6 engine with a six-speed manual gearbox and Audi’s quattro all-wheel-drive system. The bigger engine also is available with the dual-clutch gearbox.

None of this comes at a bargain price. Audi is a luxury brand with an orientation toward quality, so the tested stick-shift roadster had a starting price of $43,275.

That included all of the expected safety and luxury items: side air bags and knee air bags, stability and traction control, brake assist, automatic climate control and a sound audio system.

However, if you want to listen to your IPod, you’ll have to cough up an extra $250. Ditto if you want a navigation system ($1,950) or Bluetooth capability ($450). Other options brought the test car up to $46,625.

One option on the test car, at $1,400, was Audi’s so-called magnetic ride, which uses tiny flecks of metal in the shock absorber fluid to magnetically adjust the ride from firm to even firmer. The difference is noticeable, but the stiffer sport setting improves the handling only marginally while substantially degrading the ride.

Even on the “comfort” setting, the handling is precise. But the most important factor is the quattro AWD, which enables the TT to take a set in sharp corners and hold it.

With the V-6 and the six-speed manual, the TT has more than ample power, although first gear has a ratio so low you quickly run out of revs. Zero to 60 comes up in slightly more than five seconds. But there’s also plenty of torque to run the TT at city speeds in fifth gear, with sixth available for highway cruising.

Clutch action is light and progressive, making the TT easy to drive smoothly. The shifter works firmly and accurately, although occasionally it gets balky.